The innovations and related subject matter disclosed herein (collectively referred to as the “disclosure”) concern systems configured to transfer heat from one fluid to another fluid, and more particularly, but not exclusively, to systems having a modular configuration. Some systems are described in relation to cooling electronic components by way of example, though the disclosed innovations may be used in a variety of other heat-transfer applications.
With the recent explosive growth of cloud-based services, the number of networked computers and computing environments, including servers, as substantially grown over the past several years. As used herein, the term “server” generally refers to a computing device connected to a computing network and running software configured to receive requests (e.g., a request to access or to store a file, a request to provide computing resources, a request to connect to another client) from client computers also connected to the computing network.
The term “data center” (also sometimes referred to in the art as a “server farm”) loosely refers to a physical location housing one or more servers. In some instances, a data center can simply comprise an unobtrusive corner in a small office. In other instances, a data center can comprise several large, warehouse-sized buildings enclosing tens of thousands of square feet and housing thousands of servers.
Regardless of their size, data centers and the servers they house consume vast amounts of electrical power. Although operating servers account for a major portion of the power consumed by a given data center, cooling the servers using conventional approaches accounts for another significant portion of the consumed power.
Typical commercially-available servers have been designed to be cooled at least partially by air within the data center. Such servers usually comprise one or more printed circuit boards having a plurality of operable, heat dissipating devices (e.g., memory, chipsets, microprocessors, hard drives, etc.) mounted thereto. The printed circuit boards are commonly housed in an enclosure having vents configured to direct external air from the data center into, through and out of the enclosure. The air absorbs heat dissipated by the operable components. After exhausting from the enclosure, the heated air mixes with air in the data center and an air conditioner cools the heated data center air, consuming large amounts of energy in the process.
In general, higher performance server components dissipate correspondingly more power. However, the amount of heat that conventional cooling systems can suitably remove from the various operable devices corresponds, in part, to the extent of air conditioning available from the data center or other facility, as well as the level of power dissipated by adjacent components and servers. For example, the temperature of an air stream entering a server in such a data center can be influenced by the level of power dissipated by, and proximity of, adjacent servers, as well as the temperature of the air entering the data center (or, conversely, the rate at which heat is extracted from the air within the data center).
In general, a lower air temperature in a data center allows each server component cooled by an air flow to dissipate a higher power, and thus allows each server to operate at a correspondingly higher level of performance. Consequently, data centers have traditionally used sophisticated air conditioning systems (e.g., chillers, vapor-cycle refrigeration) to cool the air (e.g., to about 65° F.) within the data center to achieve a desired degree of cooling (e.g., corresponding to a desired performance level). Some data centers provide chilled water systems for removing heat from the air within a data center. However, rejecting heat absorbed by air in a data center using sophisticated air conditioning systems, including conventional chilled water systems, consumes high levels of power, and is costly.
In general, heat dissipating components spaced from each other (e.g., a lower heat density) can be more easily cooled than the same components placed in close relation to each other (e.g., a higher heat density). Consequently, data centers have also compensated for increased power dissipation (corresponding to increased server performance) by increasing spacing between adjacent servers. Nonetheless, relatively larger spacing between adjacent servers reduces the number of servers in (and thus the computational capacity of) the data center compared to relatively smaller spaces between adjacent servers.
Therefore, there exists a need for an effective and low-cost cooling alternative for cooling electronic components, such as, for example, rack mounted servers within data centers. There also remains a need for low-profile heat exchange assemblies (e.g., integrated heat sink and pump assemblies) configured to fit within commercially available servers having a vertical component height of less than 1.75 inches, or less. There also remains a need for heat-transfer systems for cooling varying numbers of servers within a given array of servers. In particular, there remains a need for reliable cooling systems configured to cool a variety of densities of server components within a rack, with a rack having from one to 42 servers being but one example of a desirable range of server densities to be cooled. There also remains a need for heat transfer systems configured to cool servers within a data center without employing costly air conditioning systems or chilled water systems.